1 /*
2 * Copyright (c) 2018 The WebRTC project authors. All Rights Reserved.
3 *
4 * Use of this source code is governed by a BSD-style license
5 * that can be found in the LICENSE file in the root of the source
6 * tree. An additional intellectual property rights grant can be found
7 * in the file PATENTS. All contributing project authors may
8 * be found in the AUTHORS file in the root of the source tree.
9 */
10
11 #include "modules/audio_processing/agc2/gain_applier.h"
12
13 #include <math.h>
14
15 #include <algorithm>
16 #include <limits>
17
18 #include "modules/audio_processing/agc2/vector_float_frame.h"
19 #include "rtc_base/gunit.h"
20
21 namespace webrtc {
TEST(AutomaticGainController2GainApplier,InitialGainIsRespected)22 TEST(AutomaticGainController2GainApplier, InitialGainIsRespected) {
23 constexpr float initial_signal_level = 123.f;
24 constexpr float gain_factor = 10.f;
25 VectorFloatFrame fake_audio(1, 1, initial_signal_level);
26 GainApplier gain_applier(true, gain_factor);
27
28 gain_applier.ApplyGain(fake_audio.float_frame_view());
29 EXPECT_NEAR(fake_audio.float_frame_view().channel(0)[0],
30 initial_signal_level * gain_factor, 0.1f);
31 }
32
TEST(AutomaticGainController2GainApplier,ClippingIsDone)33 TEST(AutomaticGainController2GainApplier, ClippingIsDone) {
34 constexpr float initial_signal_level = 30000.f;
35 constexpr float gain_factor = 10.f;
36 VectorFloatFrame fake_audio(1, 1, initial_signal_level);
37 GainApplier gain_applier(true, gain_factor);
38
39 gain_applier.ApplyGain(fake_audio.float_frame_view());
40 EXPECT_NEAR(fake_audio.float_frame_view().channel(0)[0],
41 std::numeric_limits<int16_t>::max(), 0.1f);
42 }
43
TEST(AutomaticGainController2GainApplier,ClippingIsNotDone)44 TEST(AutomaticGainController2GainApplier, ClippingIsNotDone) {
45 constexpr float initial_signal_level = 30000.f;
46 constexpr float gain_factor = 10.f;
47 VectorFloatFrame fake_audio(1, 1, initial_signal_level);
48 GainApplier gain_applier(false, gain_factor);
49
50 gain_applier.ApplyGain(fake_audio.float_frame_view());
51
52 EXPECT_NEAR(fake_audio.float_frame_view().channel(0)[0],
53 initial_signal_level * gain_factor, 0.1f);
54 }
55
TEST(AutomaticGainController2GainApplier,RampingIsDone)56 TEST(AutomaticGainController2GainApplier, RampingIsDone) {
57 constexpr float initial_signal_level = 30000.f;
58 constexpr float initial_gain_factor = 1.f;
59 constexpr float target_gain_factor = 0.5f;
60 constexpr int num_channels = 3;
61 constexpr int samples_per_channel = 4;
62 VectorFloatFrame fake_audio(num_channels, samples_per_channel,
63 initial_signal_level);
64 GainApplier gain_applier(false, initial_gain_factor);
65
66 gain_applier.SetGainFactor(target_gain_factor);
67 gain_applier.ApplyGain(fake_audio.float_frame_view());
68
69 // The maximal gain change should be close to that in linear interpolation.
70 for (size_t channel = 0; channel < num_channels; ++channel) {
71 float max_signal_change = 0.f;
72 float last_signal_level = initial_signal_level;
73 for (const auto sample : fake_audio.float_frame_view().channel(channel)) {
74 const float current_change = fabs(last_signal_level - sample);
75 max_signal_change = std::max(max_signal_change, current_change);
76 last_signal_level = sample;
77 }
78 const float total_gain_change =
79 fabs((initial_gain_factor - target_gain_factor) * initial_signal_level);
80 EXPECT_NEAR(max_signal_change, total_gain_change / samples_per_channel,
81 0.1f);
82 }
83
84 // Next frame should have the desired level.
85 VectorFloatFrame next_fake_audio_frame(num_channels, samples_per_channel,
86 initial_signal_level);
87 gain_applier.ApplyGain(next_fake_audio_frame.float_frame_view());
88
89 // The last sample should have the new gain.
90 EXPECT_NEAR(next_fake_audio_frame.float_frame_view().channel(0)[0],
91 initial_signal_level * target_gain_factor, 0.1f);
92 }
93 } // namespace webrtc
94